1. Field of the Invention
This invention relates to solid-state sources for millimeter wave (MMW) RF power, and to high power sources for W-band applications in particular.
2. Description of the Related Art
Sources of medium and high power, MMW radiation can be applied in communications systems and in directed energy weapons. While lower frequency MMW wave applications can now be satisfied with solid-state sources, high power sources for the W-band (75 GHz to 110 GHz) traditionally incorporate tubes such as magnetrons or Gyrotrons. Gyrotrons are effective because the large output power is combined with a very high gain antenna to produce a large power-aperture. However, such tubes are expensive, bulky, fragile, and require high voltage electrical power. Thus MMW sources incorporating tubes are not readily portable.
Semiconductor devices are now available for use as oscillators or amplifiers in the W-band, but the available power output from each semiconductor device may be limited to no more than a few watts. Thus medium and high power solid state W-band sources may use quasi-optical methods that combine the power output from a large plurality of semiconductor devices within a waveguide or in free space. Approaches that have been suggested for combining the power output from plural semiconductor devices include the reflect array amplifier described in U.S. Pat. No. 6,765,535, the grid array amplifier described in U.S. Pat. No. 6,559,724, and the lens array or tray amplifier described in U.S. Pat. No. 5,736,908.